Adhesive tape dispensers are well known devices. For example, U.S. Pat. No. 4,097,328 (Urushizaki) teaches an adhesive tape dispenser used to apply cellophane adhesive tape and to automatically cut it. The tape dispenser includes a spring-loaded swing member, a tape press roller mounted on the bottom of the swing member, and a blade-carrying disc mounted to be rotatable as the swing member is pivoted up and down. U.S. Pat. No. 7,320,351 (Chern) teaches an adhesive tape dispenser that includes a housing comprising a rear spring, a forward opening, and a forward tape press roller; a tape dispensing unit urged by the spring and comprising a tape mount with an adhesive tape roll rotatably put thereon; a push member projected from the opening; and a cutter unit pivotably mounted in the housing comprising a front cutting blade and a top ridge. Placing the cutter on a surface to be sealed with the tape slightly projected from the opening and adhered on the surface and sliding the cutter will press the tape against the surface by the tape press roller for adhering thereto. After dispensing a desired length of the tape, pushing the push member will cause it to press down and pass over the ridge and press the blade to cut the tape off its roll with the spring being compressed. This adhesive tape dispenser is capable of being operated with one hand.
FIG. 1 is a perspective view of a tape cutter (adhesive tape dispenser) disclosed in U.S. Pat. No. 7,320,351 (Chern) with the side plate removed. The cutter comprises a housing 101 consisting of two mated side plates. Within the housing 101 there is provided at least one tab at one side plate, each tab adapted to snugly insert into a hole (not shown) at the other side plate for fastening both side plates together, bar 113 projected forwardly from a rear end, a first shaft 111 at a forward opening with tape press roller 115 rotatably mounted thereon, and second shaft 112 projected laterally from one side plate.
The cutter further comprises tape dispensing unit 102 including tubular tape mount 121 with an adhesive tape roll to be rotatably put thereon, push member 122 projected from the opening, a tape guide below push member 122 for pressing onto a tape (not shown), and platform 123 a proximate tape guide. The platform 123 and a tape guide are adapted to facilitate the pulling of tape out of the cutter.
The cutter further comprises coil spring 104 put on bar 113 and biased between an inner wall of the cutter and a rear recess of tape dispensing unit 102 such that tape dispensing unit 102 is able to move closer to the inner wall of the cutter by compressing spring 104 in a tape cutting operation after dispensing a tape as detailed later. The cutter further comprises cutter unit 103 having a rear tubular portion rotatably mounted on second shaft 112 and including front cutting blade 131, mounting plate 132 for fixedly fastening blade 131 onto a front end of a block member, and top ridge 134 disposed proximate push member 122.
Referring to FIG. 1, in operation, the cutter is placed on a surface to be sealed with an open end of adhesive tape roll 105 slightly projected from the opening and adhered on the surface. Next, the cutter is made to slide on the surface with tape 105 pressed against the surface by tape press roller 115 for adhering tape 105 to the surface. When a desired length of tape 105 has been put thereon, a user may push member 122 rearward to press down and pass over ridge 134 until ridge 134 is stopped by an edge of the opening. Also, blade 131 is pressed to cut tape 105 off its roll with spring 104 being compressed.
Occasionally, during operation of one-handed adhesive tape dispensers, such as the one discussed above, tape can jam inside of the dispenser causing an inconvenience to the end user. The end user then has to take apart the two halves, rethread the dispenser, and start again. The problem can occur when the end user does not complete the full stroke of the applicator button. When this happens, the blade may still come in contact with the tape and the tape tears. As result, the tape can accumulate behind the blade. When the applicator button is released, the tape can spring forward and hit the blade before it is retracted causing the tape to jam inside of the dispenser.
U.S. Ser. No. 61/327,125 (Hagglund et al.), filed on Apr. 23, 2010, discloses a tape dispenser for single hand operation that overcomes some of these disadvantages. The disclosed tape dispenser resists jamming due to tape accumulation behind the blade by providing a pivotable lever arm on the blade holder assembly that can be urged suddenly downward by contact with a wedge, an upper pin, and a lower pin attached to a back plate when a push button assembly attached to the back plate is urged rearward by a user. The provided adhesive tape dispenser delays contact of the blade with the adhesive tape when the pushbutton assembly is urged rearward compared to the prior art and then quickly cuts the tape. The delayed, quick downward motion of the cutting blade allows for fast cutting action of the blade on the adhesive tape while minimizing the contact time of the blade or parts of the blade assembly with the tape. The minimized contact time can significantly reduce tape jamming inside of the dispenser. However, the disclosed tape dispenser for single handed operation does not completely eliminate tape jams which can occur from blade-tape interference after the tape is cut.
Thus, there is a need for adhesive tape applicators that can be operated with one hand, are simple to operate and manufacture, and which resist jamming due to tape accumulation behind the blade. There is also a need for tape applicators that can eliminate blade-tape interference after the tape is cut.